Design and performance of cost-effective green engineered cementitious composites with low drying shrinkage and self-healing

Abstract

Despite its excellent mechanical properties and crack control ability, engineered cementitious composite (ECC) was still facing challenges such as high cost, high carbon footprint, high shrinkage, and insufficient self-healing ability in natural environments for engineering applications. This study designed and developed a new ECC with characteristics of low-cost, green, ultra-high ductility, low drying shrinkage and self-healing. The effects of superabsorbent polymer (SAP) and light-burned magnesia oxide (LB-MgO) on the micro and macro mechanical properties of ECC were studied; the self-healing performance evaluation system of ECC in natural environment was established; the shrinkage regulation mechanism of SAP and LB-MgO on ECC was revealed; the microstructure, pore structure and hydration mechanism were analyzed. The study showed that the addition of SAP and LB-MgO can effectively reduce the fracture toughness and shrinkage of the matrix, improve the strain hardening strength index and energy index of ECC, and obtain the self-healing ability in the natural environment, which can continue to maintain its durability. This kind of ECC helps improve the long-term durability of the structure and meets high performance requirements while reducing material costs and environmental impact effectively.